1 Features
• Integrated proportional-integral (PI) control
– Standalone operation from nonvolatile memory
(NVM)
– Programmable proportional and integral gain
– Comparator input for output clamping
– Programmable min, max, and common-mode
values for output
– Programmable loop-phase inversion
• AFE639D2
– I2C controller for external digital temperature
sensor interface
– 12-bit DAC output: 4-LSB DNL, 1-LSB DNL
• AFE539A4
– 10-bit ADC input: 2-LSB INL, 1-LSB DNL
– 10-bit DAC output: 1-LSB INL and DNL
• AFE439A2
– 8-bit ADC input: 1-LSB INL and DNL
– 7-bit duty-cycle PWM output
• Programmable comparator for fault management
• High impedance output on DAC channel when
VDD is off
• Automatically detects I2C or SPI
– 1.62-V VIH with VDD = 5.5 V
• VREF/MODE pin selects between programming
and standalone modes
• User-programmable NVM
• Internal, external, or power supply as reference
• Wide operating range
– Power supply: 1.8 V to 5.5 V
– Temperature range: –40˚C to +125˚C
• Tiny package: 16-pin WQFN (3 mm × 3 mm)

2 Applications
• Laser
• Chemistry and gas analyzer
• Mechanically scanning LIDAR
• Robot sensing module
• Mobile robot sensing module
• Seeker front end

3 Description
The 8-bit AFE439A2, 10-bit AFE539A4, and 12-bit
AFE639D2 (AFEx39xx) are smart analog front ends
(AFE) for thermoelectric cooling (TEC) control using
voltage or PWM output. The AFE639D2 supports an
I2C controller interface to interface with external digital
temperature sensors. The AFE639D2 and AFE539A4
support voltage output and AFE439A2 supports PWM
output. The AFEx39xx support a comparator channel
for fault management. These devices also support
Hi-Z power-down mode and Hi-Z output on the DAC
channel during power off. These devices have an
integrated state machine that is preprogrammed as
a proportional-integral (PI) controller. The AFEx39xx
are an excellent choice for TEC control, temperature
control, and dynamic headroom control applications.
The AFEx39xx integrate advanced features, internal
reference, and NVM that enable this smart AFE for
processor-less applications and design reuse.